Does a car need a PVC valve?
I think we need to "go back" a few years. Before there was PCV, there was "road draft." This was just what the name implied. This was a tube from some part of the crank case which went down under the car, and as the car moved, created a "draft" so as to help ventilate the crankcase. There was an intake breather up on the top front, generally.
When PCV came along, the road draft was replaced by the PCV into the intake vacuum
I believe, other than "smog" you could get by without PCV, but you really should have some form of "draft." I actually ran open hoses on both VC of my car this summer.........just open hoses down to the underside of the car. "Draft" if you will